Exosomes secreted from induced pluripotent stem cell ameliorate the lipopolysaccharide induced neuroinflammatory response via lncRNA-0949.

PURPOSE: To study the effect of exosomes derived from the induced pluripotent stem cells (iPSCs) in the neuroinflammatory response of microglia caused by lipopolysaccharide (LPS) and reveal the potential underlying mechanism. METHODS: A permanent microglia cell line HMO6 was activated by LPS. The features of exosomes were analyzed by nano flow cytometry, Western blot and transmission electron microscope. The RNA-seq was used to analyze the difference of noncoding RNA profiles between iPSC-Exos and HMO6 derived exosomes and proved that long no-coding RNA (lncRNA-0949) was highly expressed in the iPSC-Exos. Activated HMO6 cells were cocultured with iPSC-Exos in which lncRNA-0949 was overexpressed, knocked down or normally expressed. Quantitative real-time polymerase chain reaction (RT-qPCR), Enzyme-Linked Immunosorbent Assay and Western blot assay were adopted to analyze RNA and protein expression of inflammatory factors in HMO6 cells. RESULTS: The oxidative stress and inflammatory response of microglia were significantly attenuated with the iPSC derived exosomes treatment. LncRNA-0949 was effectively delivered into the HMO6 cells through the iPSC-Exos, which largely alleviated the production of malondialdehyde, IL-6, IL-1ß and TNF-α in HMO6 cells. Overexpression of lncRNA-0949 could enhance the anti-inflammatory effect of the iPSC-Exos, and knock-down of lncRNA-0949 impaired this availability. CONCLUSION: According to our results, lncRNA-0949 enriched exosomes from iPSC could potentially be used as a therapeutic strategy to prevent/treat neuroinflammatory diseases.

Mechanism and role of mitophagy in the development of severe infection.

Mitochondria produce adenosine triphosphate and potentially contribute to proinflammatory responses and cell death. Mitophagy, as a conservative phenomenon, scavenges waste mitochondria and their components in the cell. Recent studies suggest that severe infections develop alongside mitochondrial dysfunction and mitophagy abnormalities. Restoring mitophagy protects against excessive inflammation and multiple organ failure in sepsis. Here, we review the normal mitophagy process, its interaction with invading microorganisms and the immune system, and summarize the mechanism of mitophagy dysfunction during severe infection. We highlight critical role of normal mitophagy in preventing severe infection.

Weaning difficulty after severe pneumonia in adult-onset mitochondrial myopathy with A3243G mutation in the mitochondrial tRNA gene: A case report.

Background: Mitochondrial myopathy is a group of diseases caused by abnormal mitochondrial structure or function. The mitochondrial myopathy impacts muscles of the whole body and exhibits variable symptoms. Respiratory muscle deficits deteriorate pulmonary function in patients with severe pneumonia. Case presentation: We report the case of a male patient with severe pneumonia-induced respiratory failure. He was abnormally dependent invasive ventilator-assisted ventilation after his condition had improved. Then we found abnormal ventilator waveform and a decline in muscle strength of him. Mitochondrial myopathy was ultimately confirmed by muscle pathological biopsy and body fluid genetic testing. Vitamin B complex, coenzyme Q10, Neprinol AFD, l-arginine, and MITO-TONIC were used to improve mitochondrial function and muscle metabolism. After treatment, discomfort associated with chest tightness, fatigue, cough, and sputum disappeared, and the patient was discharged. Conclusion: This case presented an uncommon cause of difficult weaning and extubation-acute onset of mitochondrial myopathy. Muscle biopsy and genetic testing of body fluid are essential for diagnosing mitochondrial myopathy. The A3243G mutation in the MT-TL1 gene of mitochondrial DNA contributes to pathogenesis of this case.

Reducing LncRNA-5657 expression inhibits the brain inflammatory reaction in septic rats.

Our preliminary study found that the long noncoding RNA (LncRNA)-5657 can reduce the expression of inflammatory factors during inflammatory reactions in rat glial cells. However, the role played by LncRNA-5657 during septic brain injury remains unclear. In the present study, rat models of septic encephalopathy were established by cecal ligation and puncture, and then the rats were treated with a hippocampal injection small hairpin RNA (shRNA) against LncRNA-5657 (sh-LnCRNA-5657). The sh-LncRNA-5657 treatment reduced the level of neuronal degeneration and necrosis in the rat hippocampus, reduced the immunoreactivities of aquaporin 4, heparanase, and metallopeptidase-9, and lowered the level of tumor necrosis factor-alpha. Glial cells were pre-treated with sh-LncRNA-5657 and then treated with 1 µg/mL lipopolysaccharide. Sh-LncRNA-5657 transfection decreased the expression of LncRNA-5657 in lipopolysaccharide-treated glial cells and decreased the mRNA and protein levels of tumor necrosis factor-alpha, interleukin-1ß, and interleukin-6. These findings suggested that LncRNA-5657 expression can significantly reduce the inflammatory reaction during septic encephalopathy and induce protective effects against this disease. This study was approved by the Institutional Ethics Committee at the First Affiliated Hospital of Nanchang University of China (approval No. 2017-004) in 2017.

Autophagy alleviates mitochondrial DAMP-induced acute lung injury by inhibiting NLRP3 inflammasome.

AIM: Acute lung injury (ALI) is characterized by alveolar macrophage overactivation and uncontrolled pulmonary inflammation. Mitochondrial damage-associated molecular patterns (MTDs), one type of damage-associated molecular patterns (DAMPs) released from ruptured mitochondrial, can induce inflammation which participates in the pathogenesis of ALI. Despite the critical role of autophagy in inflammatory response, little is known about its function in MTDs-induced ALI. Herein we have studied how autophagy attenuates MTDs-induced ALI in vitro and in vivo. MAIN METHODS: Exogenous MTDs were injected into mice through tail vein injection or directly treated with cultured alveolar macrophage cell lines to construct MTDs-induced ALI models. Rapamycin and 3-MA were used to regulate autophagy in vivo and in vitro. The expressions of Caspase-1, IL-1ß, and their precursor were measured. Inhibition the activation of NLRP3 inflammasome to discover the candidate targets and potential molecular pathways involved in autophagy mitigating the MTDs-induced ALI. KEY FINDINGS: After treatment with MTDs the expression levels of inflammatory cytokines and NLRP3 inflammasome-associated proteins were gradually increased in vitro and in vivo. Most importantly, with autophagy enhanced by rapamycin, all the secretion of inflammation cytokine, the level of lung injury, and the expression level of NLRP3 inflammasome-associated proteins were greatly decreased in MTDs-induced mouse model. MTDs-induced inflammation and lung injury were alleviated by autophagy enhancement. Autophagy can function as an effective way to alleviate inflammation in MTDs-induced ALI by inhibiting NLRP3 inflammasome and may represent a therapeutic target in modulating MTDs-induced inflammatory response.

[Generation of sepsis encephalopathy patient-specific inducible pluripotent stem cells with urine cells].

OBJECTIVE: To recombine the induced pluripotent stem cells (iPSC) derived from the urine of septic encephalopathy (SE) patients, and provided a specificity cell model to explore the mechanism of the neuronal damage and treatment for SE patients. METHODS: Urine of SE patient was collected, and tubular epithelial cells were isolated and cultured from the urine. iPSC were derived from SE patient by introducing 4 transcription factors OCT4, Klf4, Sox2, c-Myc (OKSM) into patient-specific urine cells by Millipore's Human STEMCCATM Constitutive Polycistronic (OKSM) Lentivirus Kit. Colony morphology, alkaline phosphatase (AKP) activity, immunofluorescence staining, quantitative reverse transcription-polymerase chain reaction (RT-qPCR), and differentiation ability were used to identify the pluripetency of these iPSC lines. In addition, neurons were derived from these iPSC by inhibiting transforming growth factor-ß (TGF-ß) pathway. RESULTS: The SE-iPSC exhibited morphological and growth characteristics of human embryonic stem cell (hES), showed positivity for AKP by histochemical staining, and expressed embryonic stem cell (ESC) marker genes. There was a significant statistical difference in ESC-marker mRNA expression between the SE-iPSC and the urine cells [NANOG mRNA (2-ΔΔCt): 1.153±0.142 vs. 0.126±0.024, t = -10.688; REX1 mRNA (2-ΔΔCt): 1.419±0.206 vs. 0.103±0.066, t = -14.245; OCT4 mRNA (2-ΔΔCt): 1.233±0.176 vs. 0.201±0.022, t = -9.028; Sox2 mRNA (2-ΔΔCt): 1.334±0.119 vs. 0.159±0.017, t = -12.653, all P < 0.01]. Subcutaneous injection of iPSC into NOD-SCID mice resulted in teratomas containing tissues from all the 3 germ layers. Furthermore, neurons were successfully induced from SE-iPSC. CONCLUSIONS: The SE patient-specific iPSC could be generated from urine cells and differentiated into neurons, furthermore, the SE-iPSC cell line can be used as models for further elucidating the cellular pathology and developing therapeutic strategies for SE.

Prion seeding activity and infectivity in skin samples from patients with sporadic Creutzfeldt-Jakob disease.

Sporadic Creutzfeldt-Jakob disease (sCJD), the most common human prion disease, is transmissible through iatrogenic routes due to abundant infectious prions [misfolded forms of the prion protein (PrPSc)] in the central nervous system (CNS). Some epidemiological studies have associated sCJD risk with non-CNS surgeries. We explored the potential prion seeding activity and infectivity of skin from sCJD patients. Autopsy or biopsy skin samples from 38 patients [21 sCJD, 2 variant CJD (vCJD), and 15 non-CJD] were analyzed by Western blotting and real-time quaking-induced conversion (RT-QuIC) for PrPSc Skin samples from two patients were further examined for prion infectivity by bioassay using two lines of humanized transgenic mice. Western blotting revealed dermal PrPSc in one of five deceased sCJD patients and one of two vCJD patients. However, the more sensitive RT-QuIC assay detected prion seeding activity in skin from all 23 CJD decedents but not in skin from any non-CJD control individuals (with other neurological conditions or other diseases) during blinded testing. Although sCJD patient skin contained ~103- to 105-fold lower prion seeding activity than did sCJD patient brain tissue, all 12 mice from two transgenic mouse lines inoculated with sCJD skin homogenates from two sCJD patients succumbed to prion disease within 564 days after inoculation. Our study demonstrates that the skin of sCJD patients contains both prion seeding activity and infectivity, which raises concerns about the potential for iatrogenic sCJD transmission via skin.

Quiescin-sulfhydryl oxidase inhibits prion formation in vitro.

Prions are infectious proteins that cause a group of fatal transmissible diseases in animals and humans. The scrapie isoform (PrPSc) of the cellular prion protein (PrPC) is the only known component of the prion. Several lines of evidence have suggested that the formation and molecular features of PrPSc are associated with an abnormal unfolding/refolding process. Quiescin-sulfhydryl oxidase (QSOX) plays a role in protein folding by introducing disulfides into unfolded reduced proteins. Here we report that QSOX inhibits human prion propagation in protein misfolding cyclic amplification reactions and murine prion propagation in scrapie-infected neuroblastoma cells. Moreover, QSOX preferentially binds PrPSc from prion-infected human or animal brains, but not PrPC from uninfected brains. Surface plasmon resonance of the recombinant mouse PrP (moPrP) demonstrates that the affinity of QSOX for monomer is significantly lower than that for octamer (312 nM vs 1.7 nM). QSOX exhibits much lower affinity for N-terminally truncated moPrP (PrP89-230) than for the full-length moPrP (PrP23-231) (312 nM vs 2 nM), suggesting that the N-terminal region of PrP is critical for the interaction of PrP with QSOX. Our study indicates that QSOX may play a role in prion formation, which may open new therapeutic avenues for treating prion diseases.

Recombinant human prion protein inhibits prion propagation in vitro.

Prion diseases are associated with the conformational conversion of the cellular prion protein (PrP(C)) into the pathological scrapie isoform (PrP(Sc)) in the brain. Both the in vivo and in vitro conversion of PrP(C) into PrP(Sc) is significantly inhibited by differences in amino acid sequence between the two molecules. Using protein misfolding cyclic amplification (PMCA), we now report that the recombinant full-length human PrP (rHuPrP23-231) (that is unglycosylated and lacks the glycophosphatidylinositol anchor) is a strong inhibitor of human prion propagation. Furthermore, rHuPrP23-231 also inhibits mouse prion propagation in a scrapie-infected mouse cell line. Notably, it binds to PrP(Sc), but not PrP(C), suggesting that the inhibitory effect of recombinant PrP results from blocking the interaction of brain PrP(C) with PrP(Sc). Our findings suggest a new avenue for treating prion diseases, in which a patient's own unglycosylated and anchorless PrP is used to inhibit PrP(Sc) propagation without inducing immune response side effects.

Upregulation of miR-146a contributes to the suppression of inflammatory responses in LPS-induced acute lung injury.

Despite the critical role of microRNA in inflammatory response, little is known about its function in inflammation-induced Acute Lung Injury (ALI)/Acute Respiratory Distress Syndrome (ARDS). To investigate the potential role of microRNA146a (miR-146a) in ALI, we used lipopolysaccharide (LPS)-induced ALI rat model. Our data revealed that LPS-induced lung injury in rats resulted in significant upregulation of proinflammatory cytokine tumor necrosis factor-alpha (TNF-α), IL-6, IL-1ß, and miR-146a expression. LPS treatment also leads to higher expression of miR-146a as well as increase in secretion of TNF-α, IL-6, and IL-1ß in alveolar macrophage (AM) NR8383 cells in a time-dependent manner. Manipulation with miR146a mimic significantly suppressed LPS-mediated TNF-α, IL-6, and IL-1ß induction in NR8383 cells by repressing expression of IRAK-1 and TRAF-6. These data clearly indicate that the upregulation of miR146a suppresses inflammatory mediators in LPS induced-ALI model. Therefore, miR-146a may be therapeutically targeted as a mean to repress inflammatory response following ALI.

Glycoform-selective prion formation in sporadic and familial forms of prion disease.

The four glycoforms of the cellular prion protein (PrP(C)) variably glycosylated at the two N-linked glycosylation sites are converted into their pathological forms (PrP(Sc)) in most cases of sporadic prion diseases. However, a prominent molecular characteristic of PrP(Sc) in the recently identified variably protease-sensitive prionopathy (VPSPr) is the absence of a diglycosylated form, also notable in familial Creutzfeldt-Jakob disease (fCJD), which is linked to mutations in PrP either from Val to Ile at residue 180 (fCJD(V180I)) or from Thr to Ala at residue 183 (fCJD(T183A)). Here we report that fCJD(V180I), but not fCJD(T183A), exhibits a proteinase K (PK)-resistant PrP (PrP(res)) that is markedly similar to that observed in VPSPr, which exhibits a five-step ladder-like electrophoretic profile, a molecular hallmark of VPSPr. Remarkably, the absence of the diglycosylated PrP(res) species in both fCJD(V180I) and VPSPr is likewise attributable to the absence of PrP(res) glycosylated at the first N-linked glycosylation site at residue 181, as in fCJD(T183A). In contrast to fCJD(T183A), both VPSPr and fCJD(V180I) exhibit glycosylation at residue 181 on di- and monoglycosylated (mono181) PrP prior to PK-treatment. Furthermore, PrP(V180I) with a typical glycoform profile from cultured cells generates detectable PrP(res) that also contains the diglycosylated PrP in addition to mono- and unglycosylated forms upon PK-treatment. Taken together, our current in vivo and in vitro studies indicate that sporadic VPSPr and familial CJD(V180I) share a unique glycoform-selective prion formation pathway in which the conversion of diglycosylated and mono181 PrP(C) to PrP(Sc) is inhibited, probably by a dominant-negative effect, or by other co-factors.

[Effect of Shenfu injection on expression of lipopolysaccharide --induced microRNA-146a in alveolar macrophages].

OBJECTIVE: To study the effects of Shenfu injection (SF) on the expression of lipopolysaccharide(LPS)-induced microRNA-146a (miR-146a) in rat alveolar macrophages (AMs), and to extrapolate its potential anti-inflammatory mechanisms. METHODS: In vitro cultured rat AMs (NR8383 cells) were randomly divided into control group, LPS stimulation group, and SF stimulation group. The LPS stimulation group was challenged with a final concentration of 1 mg/L LPS, and to the control group an equal volume of phosphate buffer solution (PBS) was added instead. For SF treated group, SF in different concentrations (1 ml/L or 10 ml/L) was used during incubation of AMs for half an hour, and then LPS was added (1 mg/L final concentration). After 6 hours, the cells and were collected. MiRNA-146a expression [reverse transcription-polymerase chain reaction (RT-PCR)] in cells and tumor necrosis factor-α (TNF-α ) content [enzyme-linked immunosorbent assay (ELISA)] in culture supernatant were determined for each group. RESULTS: Both the expression of miR-146a and TNF-α content in LPS stimulation group were significantly elevated compared with control group [miR-146a (expression folds): 5.92 + 1.57 vs. 1.04 +0.38; TNF-α (ng/L): 636.93 _ 30.21 vs. 20.46 + 2.81; both P<0.05]. Compared with LPS stimulation group, the expression of miR-146a was significantly upregulated in cells in both 1 ml/L and 10 ml/L SF stimulation groups, but TNF- α content was significantly reduced in the supernatant [miR-146a (expression folds): 7.02 + 0.91, 8.11 ± 1.07 vs. 5.92 -1.57; TNF-α (ng/L): 447.24 +21.29, 357.83 +19.73 vs. 636.93 +30.21, all P<0.05] in a dose-dependent manner (both P<0.05). CONCLUSION: SF could up-regulate miR-146a expression in AMs in a dose-dependent manner, and it was speculated that miR-146a might be involved in the anti-inflammatory processes with SF treatment.

[A clinical study on organ protective effect of early high-volume hemofiltration (HVHF) in patients with multiple organ dysfunction syndrome (MODS) complicated by acute kidney injury (AKI)].

OBJECTIVE: To investigate the organ protective effect of early continuous HVHF in patients with MODS complicated by AKI. METHODS: 117 patients requested HVHF in ICU due to MODS/AKI were enrolled from June 2006 to June 2011 for clinical data collection. The patients were categorized, by RIFLE scale (R-risk of renal dysfunction, I-injury to the kidney, F-failure of kidney, L-loss of kidney function, E-end stage kidney disease), into three groups: RIFLE-R (n = 15), RIFLE-I (n = 23) and RIFLE-F (n = 79). The values of their serum creatinine (SCr), oxygenation index (PaO(2) /FiO(2) ), extravascular lung water index (EVLWI), blood lactic acid (Lac), prothrombin time (PT), aspartate aminotransferase (AST), acute physiology and chronic health evaluation II (APACHE II) score were recorded, at the beginning of, and within 72 hours after HVHF. The 90-day survival rate in each group was calculated. RESULTS: No significant difference was found between RIFLE-R and RIFLE-I group, within 72 hours after HVHF, in SCr, PaO(2) /FiO(2) , EVLWI, Lac, PT, AST, or APACHE II score. The mean values of SCr, EVLWI, Lac, PT, AST, APACHE II score, within 72 hours after HVHF in the RIFLE-F group were significantly higher in comparison with RIFLE-R, and RIFLE-I group [SCr (µmol/L): 260.50±35.51 vs. 83.61±21.07, 89.71±23.81 ; EVLWI (ml/kg): 12.18±2.11 vs. 10.94±1.50,10.76±1.92; Lac (mmol/L): 2.40±0.56 vs. 1.58±0.27, 1.68±0.35; PT (sec): 14.14±1.50 vs. 12.67±1.18, 12.51±0.94; AST (U/L): 96.19±18. 84 vs. 47.91±12.85, 56.39±13.44; APACHE II score: 20.17±2.61 vs. 17.79±2.65, 18.53±2.87, P< 0.05 or P< 0.01]; However, the PaO(2) /FiO(2) (mm Hg, 1 mm Hg = 0.133 kPa) value in RIFLE-F group was found significantly lower compared to RIFLE-R and RIFLE-I group (202.80±19.07 vs. 245.24±21.18, 250.63±25.56, P< 0.01). No statistical significant difference was found in the 90-day survival rate among RIFLE-R, RIFLE-I and RIFLE-F group (66.67%, 65.22%, 63.29%, respectively, P> 0.05). CONCLUSION: Early HVHF has protective effect against organs injury in patients with MODS and AKI.